There are a variety of window coverings used at the present which hang from a headrail mounted onto a vertical wall surface or from the ceiling of a room, and which consist generally of an elongated metal or plastic housing having an open top. One example of such a window covering is what is sometimes termed a "venetian blind" which has a plurality of slats that can be manipulated by cords to vary the amount of light to pass through the blind or to raise and lower the blind to any desired height. Another form of such window covering includes an extent of flexible pleated material which can be raised or lowered to any desired vertical position with the window covering material folding onto itself along the pleat lines.
It is known to enclose the headrail for such window covering units with a cornice permanently affixed to the headrail and/or wall by threaded means or the like so that once assembled to the headrail, the headrail, cornice and blind are a unit. Futhermore, the cornice is sometimes attached to the vertical wall only or sometimes to both the wall and the headrail. Such arrangements are impractical for many mounting locations, in that the presence of the cornice makes the headrail difficult to mount to the wall or ceiling. Also, an adjoining wall may reduce the available end space which could leave the ends of the window covering spaced inwardly so as not to cover a slit of a window, for example. Still further, such arrangements are rather bulky and heavy, and do not for that reason lend themselves to easy replacement in the event of damage, nor are they readily taken down for cleaning.